AN2836 datasheet(30/57 Pages) STMICROELECTRONICS

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Designing an application with L6225, L6226, L6227

AN2836

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Doc ID 15084 Rev 1

This configuration has to be used when two separate loads are driven, since the ICs have

only two ENABLE inputs, one for the full bridge A and the other for the bridge B. In this case

pulling to GND one of the two ENABLE pins disables only one load (see Figure 31 to 33).

This configuration can also be used if a 2.8 A OCD threshold is desired (instead of 5.6 A).

Half-bridge 1 and the half-bridge 2 of the bridge A are connected in parallel and the same is

done for the bridge B as shown in Figure 31 to 33. In this configuration, the peak current for

each half bridge is still limited by the bond wires for the supply and sense pins so the

dissipation in the device is reduced, but the peak current rating is not increased. Using this

configuration with L6226, two separate resistors connected to pins PROGCLA and

PROGCLB must be used. With L6227, two separate RC networks should be used on the RC

pins. When two different loads are driven (see Figure 33) by the two equivalent half bridges,

two separate sensing resistors are needed, while if the two equivalent half bridges drive two

separate loads, they must be connected from the OUT pins to VS (see Figure 33) to make

the PWM current control work properly.

In this configuration, the resulting bridge has the following characteristics (typical values).

●

Equivalent device: full bridge

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RDS(on) HS + RDS(on) LS 0.73 Ω typ. value at TJ = 25°C

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1.4 A max RMS load current

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2.8 A OCD threshold

Figure 31.

L6225 parallel connection with lower overcurrent threshold

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